Apparatus for applying coating material to the wall of a bore in a workpiece



H. G. SPIER APPARATUS FOR APPLYING COATING MATERIAL TO Jan. 7, 1964 THE WALL OF A BORE IN A WORKPIECE 4 Sheets-Sheet 1 Filed 001:. 13, 1961 on S 3m R m 5 m W G s n G n H I I T3 Y B 3 w E S Nm x 3m I 1 III F mm AGENT H. G. SPIER APPARATUS FOR APPLYING COATING MATERIAL TO Jan. 7, 1964 THE WALL OF A BORE IN A WORKPIECE 4 Sheets-Sheet 2 Filed Oct. 13, 1961 Fl G. 2.

INVENTOR Hans G.Spier Mam:

AGENT Jan. 7, 1964 SPIER 3,117,026

, H. G. APPARATUS FOR APPLYING COATING MATERIAL TO THE WALL OF A BORE IN A WORKPIECE Filed Oct. 13. 1961 4 Sheets-Sheet 5 FIG.4.

FIG.5.

I INVENTOR l Hons G. Spier Jan. 7, 1964 H. G. SPIER APPARATUS FOR APPLYING COATING MATERIAL TO THE WALL OF A BORE IN A WORKPIECE 4 Sheets-Sheet 4 Filed Oct. 13, 1961 r .P Rd 0 N G E Vs m u I my AGENT 3d was Patented Jan. 7, ram

APPARATUS FOR Al lifsfihG CGATENG MATE- ii) WAi-L GE A. BQKLE EN A WGRK- PEJCE Hans G. pier, Media, Pan, assignor to Bahia/immine- Hamilton Qorporation, a corporation of Pewsylvania Filed et. 13, 196i, fier. No. 144353 7 tllaims. (Qt. 113215) This invention relates to apparatus for applying a coating to the wall of a bore in a workpiece.

Although adapted to wide use in this field, the illustrated embodiment is particularly suitable for automatically controlled application of a fluid coating to a bored hole in a macmnery component into which another part is to be pressed with an interference fit, in order to facilitate the pressing operation without scoring of the contact surfaces, and to aid in the control of tightness of such press fits, as well as to provide a friction lubricant desirable for removing the same part from the bored hole when required. These conditions are typical of railroad car wheels, which are pressed onto their axles with a precise fit, in order to withstand all operational forces in railroad service safely, and at the same time should allow the removal of the wheels from the axles for replacement without destructive damage to the wheels or axles.

In order to coat the wheel bores properly, a mixture of basic carbonate white lead and boiled linseed oil is usually applied to the press-it surfaces in a volume, surface area and degree of uniformity prescribed by practical experience. In the past the coating has generally been applied by hand by a skilled mechanic in an amount estimated by him to be sufiicient, but experience shows that in practice there is occasional difiiculty or damage from scoring, due apparently to insufiiciently uniform application, and frequently too much or too little coating material has been deposited.

An object of the invention is to provide apparatus for mechanically and uniformly applying a controlled amount of coating material to the wall of a bore in a workpiece so as to minimize reliance on personal skill.

Another object of the invention is to provide coating apparatus of the aforesaid type, which is easily adaptable to automatic operation and sequencing.

A further object of the invention is to provide coating apparatus which within a predetermined range is automatically adjusted in accordance with the diameter of a bore in a workpiece to be treated.

An additional object of the invention is to provide apparatus for applying coating material to the Wall of a bore in a workpiece by means of a rol -on operation allowing close control over the amount deposited; which will avoid Waste and air contamination due to dispersion of the coating material as would be encountered in brushing or spraying operations.

It is also an object of the invention to provide apparatus in which an applicator for treating the wall of a bore is supplied with coating material in a retracted position so that this phase of the operation can easily be observed and controlled, the material being fed to the outside of the applicator in a manner such as to eliminate narrow internal channels which would be subject to clogging upon the formation of deposits of heavier components of the coating material.

Further objects, features and advantages of the invention will become apparent as the description proceeds.

in the drawings which illustrate an embodiment of my invention by way of example,

FIG. 1 is an elevational section;

PEG. 2 is an end view taken in the direction of the arrow 2 in FIG. 1, but shown on a reduced scale;

FIG. 3 is a plan view dnawn on the reduced scale of FIG. 2;

FIG. 4 is a fragmentary, diagrammatic section generally similar to FIG. 1, but drawn on a reduced scale and showing the apparatus positioned adjacent a workpiece to be treated;

FIGS. 5 and 6 are sections similar to FIG. 4, but showing the apparatus in different operating positions.

Referring now to the drawings, there is shown a base 2th of preferably welded construction to which are secured at one end by screws 21 a split mounting collar 22 and a bearing collar 23, and adjacent the other end a bearing 24 with cooperating bearing cap 25. Rotatably mounted in bearings 23 and 24 is an assembly comprising a drive tube 26 and a drive pulley 27 rigidly secured thereto by screws 28. Lubricating means 23a and 25a are provided for the hearings. A preferably air driven motor 29 mounted on base 2%? and having a sheave 3t} thereon is connected by a belt 31 to pulley 27 for rotating drive tube 26.

Telescopically and coaxially mounted in'drive tube 26 is an assembly comprising a carrier or driven tube 32 and a guide and stop bushing 33 rigidly secured thereto by screws 34. Bushing 33 slidably engages the inner surface of drive tube 26 as best shown in the lower portion of MG. 1. A key 35 fitted in bushing 33 is slidably received in a keyway 36 in drive tube 26 so that driven tube 32 rotates with drive tube 26 and is axially reciprocable therein. FEGURE 1 shows the driven tube 32 in its inner or retracted position. An abutment or stop surface 37 in drive tube 26 is arnanged to engage the end 38 of bushing 33, thereby limiting axial sliding movement of driven tube 32 to the left in FIG. 1.

A cylinder 40 which is operated by fluid such as air has a cylindrical head 41 at its outer end and cooperates with a piston 42, a piston rod 43 extending through the opposite end wall 41a. Cylinder 40 is supported within driven tube 32 at one end by means of a bearing assembly 4-4 and on piston rod 43 at the other end by means of the split mounting collar 22 in which the outer end portion of piston rod 43 is rigidly clamped. Bearing assembly 44 is arranged in driven tube 32 for reciprocation therewith and is also slidable relative thereto for limited'axial movement therein from an inner abutment 45 to the left in FIG. l. The bearing assembly 44' comprises a radial and thrust type ball bearing 46, the inner race of which is mounted on cylinder head 41. This allows the outer portion of bearing assembly 44 to rotate with driven tube 32 without rotating the cylinder 44 yet transmit axial movement to tube 32 so that the cylinder and piston unit 40, 42 will serve as an actuator for reciprocation of the driven tube in the manner described later.

For admitting and exhausting compressed air to and from both sides of piston 42, piston rod 43 is composed of an inner tubular member 43a and a coaxial, spaced outer tubular member 43b so as to provide a central bore or channel 47 leading from a connection or opening at A to a forward chamber 48 adjacent the cylinder head 41, an annular separate charmel 49 being formed between tubes 43a, 43b. The latter are tightly secured to each other at their ends so that channel 49 is sealed, except for a connection or opening B adjacent one of its ends and an aperture 50 adjacent the other end, the aperture 50 leading to a return chamber 51 between piston 42 and cylinder end wall 41a. The openings A and B communicate with a conventional control valve (not shown) which has inlet and exhaust ports and is connected to a source of compressed air.

An applicator offsetting mechanism generally indicated at 52 cooperates with bearing assembly 44 and is connected to a shaft 53 on which a cylindrical applicator or idle roller 54, preferably of the felt disc type, is mounted with the aid of a wing nut 54a or the like for free rota tion. Mechanism 52 is thus interposed between the actuating means 4t), 42 and the applicator 54. Shaft 53 has an arm 55 thereon and carries a pair of parallel spaced pivots 56, the axes of which are disposed in a plane transverse to the common axis XX of the tubes 26, 32. A further pair of parallel spaced pivot 57 are provided on an offsetting bracket or head 53 and are received in extensions SSa thereof, the head 58 being rigidly secured to the outer end of driven tube 32 by screws The axes of pivots 57 are disposed in a plane parallel to the plane of the axes of pivots 56 and are parallel to the latter axes and spaced the same distance apart. Pivots 56 are connected to pivots 5'7 by a pair of offsetting arms or levers 60 which are of equal length between pivot points and parallel to each other. Each of the levers 66) is bifurcated at one end to embrace shaft arm 55 and receive the respective pivot 56. The other ends of the levers are positioned between the extensions 58a of head 58. An extension or cam 61 is provided on each of the levers 60 and urged against the front portion of bearing assembly 44 by a spring 62 which is compressed between a tensioning cap 62a in bracket 58, and an abutment 55a on shaft arm 55. Downward movement of arm 55 is limited by the bearing assembly 44 contacting earns 61, land this will determine the retracted or rest position (FIG. 1) of applicator 54, in which the applicator support shaft 53 is preferably centered, i.e., coaxial with tubes 26, 32. A stop screw 63 provides for adjustment of the retracted position if required. It will be clear that the bifurcated arms 60 are thus mounted for swinging motion along a vertical plane through the common axis XX of tubes 26, 32. to move shaft 53 from the concentric position shown in FIG- URE l to an offset position, and throughout this move ment the axis of shaft 53 is maintained parallel to the axis XX.

It should be noted that spring '62 is of sufficient strength to keep cams 61 of levers 60 in firm contact with bearing assembly 44 and to hold the applicator 54 in its central position while the air pressure in cylinder 40 is relatively low, but the spring will yield when the pressure is built up as described herein later.

Feeding means is provided to pour coating material on applicator roller 54 in a desired pattern when the roller is in the retracted position of the assembly illustrated in FIGURE 1, comprising a vertical feed pipe 64 terminating in a distributor or dispenser pipe 65 disposed above and parallel to the applicator 54 in its retracted position. In the embodiment shown, the distributor is positioned over a lateral portion of roller 54 at the side where points on the surface of the roller move upwards, which will allow ample time for absorption of coating material before it is carried to the underside of the roller from which excess material will drop off. Distributor 65 is clear of the path of parts attached to driven tube 32 and preferably is provided with longitudinally spaced orifices for discharging the coating material onto the surface of roller 54. While the apparatus is in its retracted position, a controlled stream of coating material is supplied through feed pipe 64 from a constantly agitated supply tank (not shown). Excess material will drop from roller 54 into a container 66 thereunder, from which it fiows out through a drain pipe 67 and back to the supply tank.

At the start of the operation, the parts are in the retracted or initial position shown in FIGS. 1 and 4 and motor 29 is actuated to turn tube 26 at a speed of approximately one to two revolutions per second. Key 35 will cause the carrier or driven tube 32 to participate in the rotating movement, and the offsetting mechanism 52 will also be taken along due to its head 58 being secured to the driven tube 32 at 59. As, at the start, the axis of shaft 53 coincides with the common axis XX of tubes 26 and 32, the shaft will turn about its own axis at this time. Roller 54, although freely rotatable on shaft 53, turns therewith when not in contact with any surface to be coated, due to slight friction where the roller rests on the shaft. While applicator .54 rotates, coating material is supplied through feed pipe 64 and distributor 65. The roller is thus covered uniformly with material in a desired pattern while in the retracted position. As soon as the roller moves from this position, a switch 68, previously actuated by a flange 69 fixed to head 58, will be released to stop the supply of coating material until the apparatus returns to the retracted position. It should be noted that flange 6 extends entirely around head 58 to be engage able with switch 68 in any angular position of the rotat= able head. To facilitate the handling of cap 62a, flange 69 has an opening at 69a. A

The apparatus and a workpiece such as a wheel 70 (PEG. 4) having a bore 71 to be coated will be positioned so that the axis of the bore is aligned with the common axis XX of tubes 26 and 32. By admitting air under pressure at A and connecting the opening B to exhaust, cylinder 40 is moved to the left in FIGS. 1 and 4 to push bearing assembly 44 forward in the same direction. The bearing assembly is in contact with cams 61 of the off setting mechanism 52 and will advance this mechanism, the attached carrier or driven tube 32, and the applicator roller 54 so as to position the latter within bore 71 to be coated; see FIG. 5. The foregoing movement is pe'r= formed with little resistance and at a rapid rate. When the end 33 of stop bushing 33 engages the abutment 37 in drive tube 26 (-FIG. 5) and thus the driven tube 32 is locked in extended position against additional forward movement, the pressure in cylinder 40 is built up to a preset value and cylinder 49 and bearing assembly 44 will advance further, relative to the arrested tube 32. The predetermined force of spring 62 will be overcome and bearing assembly 44 engaging the cams 61 will cause the levers 60 to swing around their pivots 57 so as to shift the applicator roller 54 from the central or concentric position of FIG. 5 to an eccentric position offset from the axis XX with the applicator 54 bearing against the wall of bore '71 to be coated; see FIG. 6. Tubes 26, 32 will continue to rotate and shaft 53 will now revolve around axis XX in the manner of a crank pin. Accord ingly, applicator 54 will roll along the inner surface of bore 71 while turning freely on the revolving shaft 53. Thereby, portions of the coating material previously de posited on the felt disks of roller 54 will be uniformly applied to the wall of bore 71. The contact pressure between rol-ler and wall of the bore is adjustable by varying the pressure of air supplied to cylinder 40.

After a predetermined time of roll-coating of the wheel bore, connection A is vented and compressed air is sup plied to connection B. Cylinder 40 will then move toward bearing'collar 23 at the right in FIG. 6, retracting the bearing assembly 44. The mechanism 52 and the applicator 54- will follow the bearing assembly under the action of spring 62 and will thus return to the central position of FIG. 5. During further movement of cylinder 4% toward bearing collar 23, the bearing assembly 44 engages the abutment 45 of driven tube 32, and the latter is taken along so that the applicator 54 and the associated parts are moved away from the wheel bore 71 and moved to the initial position shown in FIGS. 4 and 1. Flange 69 will then actuate switch 68, thereby restarting the flow of coating material onto the applicator, which is now turning again about axis XX, together with the continuously rotating tubes 26 and 32 and support shaft 53. After a short interval, applicator 54 will once more be carrying the desired pattern and amount of coating material and the apparatus will be ready to coat another bore when aligned in proper position.

As the rate of supply of coating material is adjustable, the amount of deposit formed on roller 54 is easily controllable, the roller being in its retracted position and: fully visible when material is fed thereto. Since narrow internal channels are avoided, the danger of clogging is minimized. As stated, the fluid pressi tre in cylinder 4t! may be varied and this will control the contact pressure between the applicator 54 and the wall to be coated. These adjustments and the length of time the applicator rolls around bore 71 will determine the amount of coating material applied to the Wall of the bore.

Since the applicator 54 is arranged to swing outwardly until it contacts the wall of the workpiece, it will be clear bores of various diameters can be treated without any adjustment of the mechanism so that within a predetermined range the apparatus will automatically assume a position responsive to the bore diameter. A substantial range of bore sizes may be handled without resetting the parts.

it will further be apparent that the apparatus is easily adaptable to fully automatic sequencing, for example, by using a conventional feeler as well as a timer. The feeler will serve to detect the proximity of a workpiece or wheel 79 and then actuate the cylinder 40 so that roller 54 will be automatically advanced into bore 71, the supply of coating material being stopped by disengagement of switch 68. As described, roller 54 will then automatically be brought into engagement with the wall of the bore and as motor 29 turns continuously, the roll-on operation will be carried out. The timer will serve to reverse cylinder 40 for withdrawal of roller 54 after a predetermined interval, whereupon switch 68 will be engaged to start the flow of coating material again.

Various other modifications and changes may be made without departing from the scope of my invention as defined in the appended claims.

What I claim is:

1. Apparatus for coating the wall of a bore in a workpiece, comprising (a) a base,

(12) an applicator in the form of a roller freely rotatable about its axis and initially positioned outside said bore,

(c) feeding means mounted on said base for supplying coating material to the surface of the roller from an area above said roller while the latter is in its initial position,

(d) actuating means supported on said base and operatively connected to the roller to advance said roller axially into and retract it from said bore in spaced relationship to the wall thereof,

(e) offsetting mechanism interposed between said actuating means and roller for shifting said roller, when within said bore, transversely to the axis of the bore so as to bring it into engagement with and disengage it from the wall of said bore, and

(f) a motor mounted on said base and operative to move said roller about the axis of said bore in contact with the wall thereof to apply coating material t0 said wall.

2. Apparatus for coating the wall of a bore in a workpiece, comprising (a) a base,

(1;) a carrier having a longitudinal axis and mounted on said base for axial movement and rotation about its axis,

(0) an actuator for moving said carrier axially between a withdrawn and an advanced position,

(d) a motor for rotating said carrier,

(2) offsetting mechanism secured to said carrier,

(f) a shaft mounted on said offsetting mechanism and movable thereby in parallel transversely to said axis from a position substantially coaxial with said carrier to a position offset from said axis,

(g) an applicator in the form of a roller freely rotatable on said shaft, and

(h) feeding means for supplying coating material to said roller;

(1') whereby, after positioning said apparatus and workpiece adjacent each other with the axis of the carrier, shaft, roller, and bore being substantially aligned and with the motor rotating said carrier, coating material maybe suppliedto said applicator, the carrier may be advanced to insert said applicator in said bore in spaced relationship to the wall thereof, the shaft and applicator may be offset transversely to the axis of the bore to cause the applicator to roll along the wall of the bore and apply coating material thereto, and upon completion of the coating step the applicator may be withdrawn from said bore.

3. Apparatus as defined in claim 2, in which said offsetting mechanism comprises (a) a pair of parallel motion arms, each of said arms being pivotally connected at one end to said carrier and at the other end to said shaft, and

(b) resilient means tending to maintain said shaft in coaxial relationship With said carrier.

4. Apparatus as defined in claim 3, including means on said actuator for engaging said arms and causing them to swing around their pivot connections against the force of said resilient means so as to move said shaft transversely to the axis of said carrier.

5. Apparatus as defined in claim 2, said feeding means comprising a dispenser mounted on said base in a position over at least a portion of said roller when said carrier is in its withdrawn position with the carrier and roller being substantially coaxial.

6. Apparatus for coating the Wall of a bore in a workpiece, comprising (a) a base,

(1)) a drive tube mounted on said base for rotation around its longitudinal axis,

(0) a motor for rotating said drive tube,

(d) a driven tube having inner and outer ends and telescopically, coaxially mounted in said drive tube for rotation therewith and for reciprocation therein between a retracted position and an extended position,

(e) actuating means for reciprocating said driven tube between said retracted and extended positions,

(f) stop means on said drive tube for arresting said driven tube at said extended position thereof,

(g) a shaft actuated from said driven tube,

(h) an applicator freely rotatable on said shaft,

(1') offsetting mechanism connected to and interposed between said driven tube and shaft, said mechanism being operative when said driven tube is arrested by said stop means to offset said shaft and applicator transversely from the common axis of said tubes for engaging the applicator with the wall of the bore to be coated, and

(j) feeding means for supplying coating material to said applicator while said driven tube is in its retracted position prior to engagement of the bore surface by said applicator.

7. Apparatus as defined in claim 6, said actuating means comprising (a) a piston member,

(1)) a cylinder member cooperating with the piston member,

(0) said members being disposed within the driven tube in coaxial relationship thereto with one of the members being stationary and rigidly connected to the base and the other member being movable on the stationary member for reciprocation under the action of fluid pressure, and

(d a bearing assembly supporting the movable member in said driven tube while permitting rotation of the driven tube relative to the movable member, said bearing assembly being arranged for reciprocation with said movable member and for limited axial movement relative thereto when the driven tube is arrested by said stop means, a portion of said bearing assembly being operative to actuate said offsetting mechanism,

(References on following page) UNITED STATES PATENTS Rundell June 30, 1925 Schott et a1. Nov. 30, 1948 5 Conway et a1 Mar. 11, 1952 8 Rowe May 19, 1953 Powell et a1. May 31, 1955 Gallmeyer et a1 Oct. 27, 1959 Ver Nooy Feb. 21, 1961 Freeman Feb. 6, 1962 

1. APPARATUS FOR COATING THE WALL OF A BORE IN A WORKPIECE, COMPRISING (A) A BASE, (B) AN APPLICATOR IN THE FORM OF A ROLLER FREELY ROTATABLE ABOUT ITS AXIS AND INITIALLY POSITIONED OUTSIDE SAID BORE, (C) FEEDING MEANS MOUNTED ON SAID BASE FOR SUPPLYING COATING MATERIAL TO THE SURFACE OF THE ROLLER FROM AN AREA ABOVE SAID ROLLER WHILE THE LATTER IS IN ITS INITIAL POSITION, (D) ACTUATING MEANS SUPPORTED ON SAID BASE AND OPERATIVELY CONNECTED TO THE ROLLER TO ADVANCE SAID ROLLER AXIALLY INTO AND RETRACT IT FROM SAID BORE IN SPACED RELATIONSHIP TO THE WALL THEREOF, (E) OFFSETTING MECHANISM INTERPOSED BETWEEN SAID ACTU- 